When the Sony Walkman went on sale 30 years ago, it was shown off by a skateboarder to illustrate how the portable cassette-tape player delivered music on-the-go - a totally innovative idea back in 1979.

Today, Sony is struggling to reinvent itself and win back its reputation as a pioneer of razzle-dazzle gadgetry once exemplified in the Walkman, which yesterday had its 30th anniversary marked with a special display at Sony's corporate archives.

The Japanese electronics and entertainment company lost 98.9 billion yen in the fiscal year ended March - its first annual loss in 14 years - and is expecting more red ink this year.

The manufacturer, which also makes Vaio personal computers and Cyber-shot cameras, hasn't had a decisive hit like the Walkman for years, has taken a battering in the portable music player market by Apple's iPod.

Sony has sold 385 million Walkman machines worldwide in 30 years as it evolved from playing cassettes to compact disks then minidisks and finally digital files.

Apple has sold more than 210 million iPod machines worldwide in eight years.

There is even some speculation in the Japanese media that Sony should drop the Walkman brand - a name associated with Sony's rise following its humble beginnings in 1946 with just 20 employees to one of the first Japanese companies to successfully go global.

"The Walkman's gap with the iPod has grown so definitive, it would be extremely difficult for Sony to catch up, even if it were to start from scratch to try to boost market share," said Kazuharu Miura, analyst with Daiwa Institute of Research in Tokyo.

Miura believes Sony can hope to be unique with its PlayStation 3 and PlayStation Portable video game consoles, but it has yet to offer outstanding electronics products that exploit such strengths.

The Nikkei, Japan's top business newspaper, reported recently that Sony set up a team to develop a PSP with cell-phone features. But Miura said the idea was nothing new, since the iPhone, another Apple product, has gaming features, and Sony isn't likely to have such a product soon.

Earlier this year, Sony Chief Executive Howard Stringer announced a new team of executives and promised to bring together the hardware electronics and entertainment content divisions of Sony's sprawling empire - an effort that he said will turn around Sony and restore its profitability.

But Stringer, and his predecessors, have been making that same promise for years.

When the iPod began selling like hotcakes several years ago, a Japanese reporter asked Shizuo Takashino, one of the developers of the original Walkman, why Sony hadn't come up with the idea. Afterall, the iPod seemed like something that should have been a trademark Sony product.

Takashino had been showing reporters the latest Walkman models, which played proprietary files. Sony has been criticised for sticking to such proprietary formats. One major reason for the iPod's massive popularity was that it played MP3 files, which are widely used for online music and compatible with many devices.

In a special display at Tokyo's Sony Archive building, opening to commemorate the Walkman's 30-year history, an impassioned Akio Morita, Sony's co-founder, speaks to employees in a 1989 video to celebrate the 10th anniversary of the Walkman.

"We can deliver a totally new kind of thrill to people with the Walkman," said the silver-haired Morita, proudly wearing a gray factory-worker jacket and surrounding himself with dozens of colourful Walkman machines. "We must make more and more products like the Walkman."

Morita acknowledges in the video that the Walkman doesn't feature any groundbreaking technology but merely repackaged old ones - but did so in a nifty creative way. And it started with a small simple idea - enjoying music anywhere, without bothering people around you.

The original Walkman was as big as a paperback book, and weighed 390 grams. It wasn't cheap, especially for those days, costing 33,000 yen .

But people snatched it up.

Other names were initially tried for international markets like "soundabout" and "stowaway." Sony soon settled on Walkman. The original logo had little feet on the A's in "WALKMAN."

Many, even within Sony, were sceptical of the idea because earphones back then were associated with unfashionable, hard-of-hearing old people. But Morita was convinced he had a hit.

The archival exhibit shows other Sony products that have been discontinued or lost out to competition over the years - the Betamax video cassette recorder, the Trinitron TV, the Aibo dog-shaped robotic pet.

The Walkman exhibit, which runs through until December 25, shows models that are still on sale, some about the size of a lighter that play digital music files.

Also showcased are messages from Morita and his partner Masaru Ibuka, who always insisted a company could never hope to be a winner by imitating rivals but only by dashing stereotypes.

"All we can do is keep going at it, selling our Walkman, one at a time," said Sony spokeswoman Yuki Kobayashi. "Thirty years is a milestone for Sony. But we hope the Walkman won't be seen as just a piece of history."